feat: observable tasks iterator

config.ini.example

src/HttpResponder/ObservableTasksDashboard.php

src/ObservableTaskSlotStatusUpdate.php

src/ObservableTaskTable.php

src/ObservableTaskTableSlotStatusUpdateIterator.php

src/ObservableTaskTableSlotStatusUpdateIteratorTest.php

src/ObservableTaskTableTest.php

src/SwooleTableAvailableRowsPoolTest.php

...ocketRPCResponder/ObservableTasksTableUpdateResponder.php

src/WebSocketServerConnectionTable.php